Ongoing Research Projects:
H2/O2 Steam Generator
The production of energy from renewable sources is increasing worldwide in the context of climate change. At the same time as renewables increase, there is a rising demand for energy storage and spinning network reserves, because wind and solar power is pretty unpredictable. The combustion of hydrogen and oxygen can be a clean and flexible method in order to cover both services if these gases are produced by electrolysis from excess energy of renewable generated. The exhaust gas of this combustion process is pure superheated steam and thus, there will be no greenhouse gas emissions. The development and investigation of such a stoichiometric H2/O2 steam generator is driven at the Chair of Fluid Dynamics. In contrast to earlier efforts to realize this concept, where rocket combustion technology was adapted for energy generation, in the recent investigations a swirl-stabilized burner is used for the humidified combustion of hydrogen and pure oxygen. The gases are injected into an environment of steam, which lowers the adiabatic flame temperature down to a technically applicable level. The specific challenge of the proposed H2/O2 steam generator concept is that the combustion process must be as complete as possible. No residues of hydrogen or oxygen must be in the exhaust steam, if the system is integrated in a steam cycle plant. To reach this goal the project team takes advantage from the high combustion efficiency that is usual for swirl-stabilized burners. Nevertheless, water tunnel measurements are necessary to optimize the burners flow field and mixing properties. Afterwards, selected configurations are investigated in a combustion test rig for combustion stability and efficiency.
Contact Person: Tom Tanneberger
Turbine Development and Integration with Pressure Gain Combustion Engine
One of the main challenges in the practical implementation of Pressure Gain Combustion (PGC) into gas turbines is the lack of designs for turbomachines that can cope efficiently with the PGC exhaust gas. Although still a topic of active research, it is generally accepted that conventional turbine expanders interacting with the exhaust of pressure gain combustors will have lower isentropic efficiency, compared to their design operation. In this project, we are investigating unsteady flow field exhausting from PGC and trying to develop a turbine design methodology specifically for this harsh inflow.
Contact Person: Majid Asli
Holistic Evaluation and Improvement of a Gas Turbine with a Periodic Pressure Gain Combustion
The project Holistic evaluation and improvement of a gas turbine with a periodic pressure gain combustion is part of the Collaborative Research Centre CRC 1029 “Substantial efficiency increase in gas turbines through direct use of coupled unsteady combustion and flow dynamics”. Its main focus is the thermodynamic analysis and evaluation of gas turbine cycles with pressure gain combustion, such as the pulse detonation combustion (PDC) and the shockless explosion combustion (SEC). The projects supervisors are Prof. Dr. Stathopoulos and Prof. Dr. Peitsch.
The strong periodic and instationary characteristics of the investigated thermodynamic cycles, as well as the demand for detailed exergetic analysis, disqualify the available commercially software. Therefore, a new tool is developed that will be capable of simulating the complete gas turbine cycle process, including turbo machinery, combustion and plena.
Analyzing the thermodynamic cycles of the prior mentioned combustion technologies is a core task of the project. With the ongoing development of the simulation tool and its capability of more complex modelling, we are able to have a more detailed analysis of the gas turbine cycle efficiency. Also, parametric studies will allow for a concept of part load operation.
Exergy destruction through irreversible processes is a key parameter for the determination of the maximum work possible. Especially the novel combustion concepts as well as gas dynamic phenomena in the plena will be under investigation with the goal to minimize entropy generation.
In summary, the project investigates the following core questions:
• How does the instationary behavior influence the efficiency of the thermodynamic cycles
• Where are the main losses of exergy to be found and which sources do these losses have?
• Which requirements do the components have, to achieve the theoretically efficiency advantage of pressure gain combustion cycles over the Joule-cycle in a real application?
Additional information can be found on the CRC’s website: https://www.sfb1029.tu-berlin.de/menue/sfb_1029/
Contact Person: Tim Rähse